1. Field of the Invention
The invention relates to compositions useful in the manufacture of composites, and especially prepregs, used in the preparation of composite structures, such as laminates. The invention particularly relates to compositions including epoxidized dicyclopentadiene and their use in preparing prepregs.
2. Background of the Invention
Laminates are generally manufactured by pressing, under elevated temperatures and pressures, various layers of partially cured “prepregs”. These prepregs are generally manufactured by impregnating a thermosettable epoxy resin composition into a porous substrate, such as a glass fiber mat, followed by processing at elevated temperatures to promote a partial cure of the epoxy resin in the mat to a “B-stage.” Complete cure of the epoxy resin impregnated in the glass fiber mat typically occurs during the lamination step when the prepreg layers are again pressed under elevated temperatures for a sufficient time.
Epoxy resin systems having a high Glass Transition Temperature (Tg) are often desirable in the manufacture of prepregs and the laminates prepared therewith. Such systems may offer, for example, improved heat resistance and reduced thermal expansion. These properties along with low Dielectric Constant (Dk), and Dissipation frequencies (Df) above 1.0 GHz may be required for applications such as complex printed circuit board circuitry and for higher fabrication and usage temperatures.